Shuttle for sewing-machines.



No. 649,759. Patented May l5, |900. T. E. BOBINSDN. SHUTTLE FUR SEWINGMACHINES.

(No Model.)

UNTTEE STATES PATENT OEEICE.

THOMAS C. ROBINSON, OF MALDEN, MASSACHUSETTS, ASSIGNOR OF ONE- HALF TOE. BAKER IVELOII, OF CAMBRIDGE, MASSACHUSETTS.

SHUTTLE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 649,759, dated May 15,1900.

Application filed February l2, 1898. Serial No. 670.018. (No model.) l

T0 n/ZZ whom, it may concern:

ABe it known that LTHoMAs C. ROBINSON, of Malden, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Rotary Shuttles for Sewing-Machines, of which thefollowing is a specification.

This invention has relation to sewing-ma chines, and particularly to theshuttles which are employed therein. I have found by experience that therotary or oscillatory shuttle as commonly constructed has a weakeningand deleterious effect upon the needle-thread, whether it be waxed ornot, because of the thread being dragged across the throat or thatportion of the hook member which is at the base of the hook proper andextends between the hook and the shoulder after the hook has entered theloop; and hence the object of the invention is to provide the shuttlewith means for preventing the wearing and weakening of the thread byplacing upon the hook member at the base of the hook an antifrictiondevice with which the thread may engage as it is drawn toward the centerof rotation of the hook, and thereby to greatly increase the speed ofthe machines and obtain a much larger product than heretofore.

Reference is to be had to the accompanying drawings and to the lettersand iigures marked thereon, forming a part of this specification, thesame letters and figures designating the same parts or features, as theease may be, wherever they occur.

Of the drawings, Figure l shows my improved shuttle detached in frontelevation. Fig. 2 represents an edge view of the same. Fig. 3 representsa transverse section on line 3 3 of Fig. l. Fig. 4t represents a sectionon line 4 4.- of Fig. l. Fig. 5 represents a sectional view of theshuttle in place on the driving portion of the machine, there beingillustrated a portion of a shoe being sewed and a needle. Fig. 6illustrates the loop of the needle-thread engaging the antifrictiondevice on the hook. Fig. 7 represents the end of the hook as beingbeveled oppositely to that illustrated in Figs. l and 6.

Referring to the drawings, ct indicates the body portion of the shuttle,which is formed with a central aperture a' to receive the box,

l holder, or receptacle l) for the bobbin c.

It is formed with an internal flange d2, with which a shoulder b' and aring b2 on the periphery of the bobbin-box engage to hold the latter inplace axially, though loose to turn therein. The box has a central studh3 to receive the bobbin and has on its exterior a radially-proj ectngthread-guide or loop-cheek b4,through a longitudinal groove in which theshuttlethread passes from the bobbin, there being an aperture b5 iu thebobbin-box for this purpose. A tension-spring 11G, secured in place by ascrew 117, passed into the stud b3, bears against the shuttle-thread inthe groove to furnish a sufficient resistance to the passage thereof.The bobbin-box and loop-check are held against rotation in the usual wayby means not shown.

The shuttle has a hinged lid la mounted in the usual way, so that it maybe lifted to insert a full bobbin, the hinge not being shown.

The rotary hook portion of the shuttle is beveled on both sides, so asto converge toward its outer edge, and is cut away at a2 to form athroat a3 to engage the loop of the needle-thread. The hook CZ is formedseparately from the remainder of the hook portion of the shuttle and issecured in place by screws d d or other suitable fasteners, whereby itmay be removed for the substitution of another one therefor. The inneredge of the hook is grooved, apertured, or slotted, as at d2, to receivethe point of the needle, though the location of the groove, aperture, orslot depends on the relation of the needle to the shuttle and whetherthe needle is curved or straight. The end of the hook is beveled, asshown in Fig. 6 or as in Fig. 7.

The throat a3 between the shoulder a4 and the hook of the shuttle at thebase of the hook is concaved to partially receive an antit'ricM1 tiondevice consisting of a roll e, frusto-conical in shape and journaled ona screw-stud e', arranged radially and threaded into the body of thehook portion a. The periphery of the frusto-conieal roller is groovedspirally from end to end, as at e2, for a purpose to be described.

The rcvoluble hook portion of the shuttle is mounted in the rotarysleeve f, which is rotated or oseillated bythe ordinary devices,

IOO

(not shown,) and it is so arranged that when the needle g draws a loop 2through the work the hook enters the loop, and when the takeup (notshown) draws the needle-thread taut the shuttle-thread is passed throughthe loop and a lock-stitch is formed in the usual way.

Heretofore when the hook entered the loop far enough to cause the throatat the base of the hook to engage the loop the continued revolution ofthe shuttle caused the throat to draw more of the needle-thread throughthe work and the thread slid across the throat, so as to bear againstthe shoulder or curved portion a4 of the shuttle until the shuttlecompleted practically one rotation,when the takeup devices drew up thethread to make a tight stitch. This sliding of the thread across theshoulder weakened it and tended to unwind a portion thereof, so as torender it liable to break when the take-up devices drew upon it, whereasit will be seen that in my improved shuttle the thread engages thesmaller end of the frusto-conieal roller lying in one of the groovestherein, and as the shuttle revolves the thread is drawn out and theroller is caused to rotate'by the engagement of the thread therewith,and the thread is carried in the spiral groove from the end to the baseof the roller by the rotation of the same. In other Words, enough threadis drawn out to cause the roller to rotate a sucient number of times tocarry the thread from end to end thereof. Hence the thread is not causedto slide over the throat to the shoulder, but is carried or translatedfrom the hook to the reduced portion cv of lthe shuttle without beingcaused to unwind or become otherwise weakened. Hence the roller may besaid to convey the thread from the hook without twisting, and the wallsof the grooves provide means for preventing the said twisting.

By providing the hook with the groove or rslot d2 the barb of the needleenters therein,

so that the thread may be easily withdrawn therefrom. This may beaccomplished by a slight movement of the needle toward the hook afterthe loop has been drawn through,or else the needle may pause with itspoint and barb in the line of the groove.

While I prefer at present to employ a frustoconical roller, yet it maybe seen that the antifriction device may be either cylindrical orconcave or grooved or plain.

Having thus explained the nature of the invention and described a Way ofconstructing and using the same, though without attempting to set forthall of the forms in which it may be made or all of the modes of its use,I declare that what I claim isl. A shuttle having a hook, and anindependently-movable antifriction device for the loop between theshoulder and the point.

2. A shuttle provided with a hook and hav ing a device in the throat forconveying the thread without twisting from the hook to the shoulder.

3. A shuttle provided with a roller having its axis arranged tointersect the periphery of the shuttle, said roller being located behindthe point of the hook.

4. A shuttle having a hook member and having a spirally-grooved rollerjournaled therein behind the point of the hook.

5. A shuttle provided with a hook and with a frusto-conicalspirally-grooved roller journaled therein behind the point of the hook.i

6. A circular shuttle cut away to form a4 shoulder and a hook, the saidhook being grooved between its edges on its inner face to receive thepoint of the needle.

In testimony whereof I aiX my signature in presence of two witnesses. l

THOMAS C. ROBINSON. Witnesses:

A. D. HARRISON, P. W. PEZZETTI.

